Veronica Roth shot to literary stardom with her best-selling Divergent series. Then, she went from YA fame to being a household name when the big-screen adaptation of the series' first installment – starring Shailene Woodley, Kate Winslet, Ansel Elgort and Miles Teller – hit theaters last year.

[YOUTUBE "suZcGoRLXkU"] The full trailer for Insurgent, the follow-up to March's blockbuster film Divergent, was released Friday, and fans of Veronica Roth's book series were surprised to see a mysterious box that featured prominently.

Veronica Roth, author of the wildly successful Divergent and its sequels, may have made quite a name for herself in the world of young-adult fiction, but writing the action trilogy required tapping into a very personal struggle – her ongoing battle with anxiety.

As Beatrice "Tris" Prior, the book and film's 16-year-old protagonist and narrator, Woodley lives in a futuristic dystopian Chicago, where society is broken into five factions, each dedicated to a different virtue. Abnegation (where Beatrice was raised) is for the selfless, Dauntless is for the brave, Amity is for the peaceful, Candor is for the honest and Erudite is for the intelligent.